The purpose of the GENETICS CORE is to provide for genetic analysis of genomic DNA samples collected by the Research PROJECTS. Centralized genotyping of human and primate samples will maximize our efficiency by utilizing consistent methods for carrying out and interpreting genotyping data. This CORE will have four primary goals, which are to a) extract genomic DNA from peripheral blood or saliva from individual PROJECTS;b) to genotype the serotonin transporter promoter repeat polymorphism 5-HTTLRR in human and primate samples;c) to genotype single nucleotide polymorphisrns (SNPs) and a repeat polymorphism from five serotonin-related genes in human samples;and dj to genotype DNA variants showing genetic association in a replication sample of human samples. The CORE will work closely with the PROJECTS and with the biostatistics and imaging COREs to allow efficient sharing and analysis of genotypic data.